An improved torque type gravity gradiometer with dynamic modulation

Traditional torque type gravity gradiometer has an important pole in gravity gradient measurements, while it is relatively inefficient and with the precision of about 1 E mainly caused by the static operating mode. In this paper, we develop an improved torque type gravity gradiometer to improve the measuring efficiency, which is based on the dynamic modulation. The dynamic modulation keeps the gradiometer rotating on a turntable steadily, measures the deflection angle of the torsion pendulum continuously and then obtains the gravity gradients. The result shows that after using the improved gradiometer, the gradients W xz and W yz are obtained with precisions of 0.45 E and 0.32 E respectively in a cycle of 20 min.